i Register
In some senses, attollent is marked as obsolete. Watch for register when choosing this word.
adj
Lifting up, raising (said of muscles, especially the levator palpebrae superioris).
And here I might instance the peculiar and artificial structure of the trochlearis, and the augmentation of its power by the trochlea; the magnitude and strength of the attollent muscle, somewhat exceeding that of its antagonist
noun
A raising or lifting muscle.